Document with an unforgeable surface

ABSTRACT

Documents and data, patterns, etc., applied thereto, which are present in the form of a surface relief, in particular in the form of embossed characters, are provided partially in the area of this surface relief with luminescent substance which is testable visibly and by machine. The luminescent substance is introduced either into raised or into depressed areas of the surface relief, so that characteristic features of the surface relief are reflected in its spatial distribution. The data can thus be tested for falsification and at the same time for authenticity in a simple way.

The present invention relates to a document with a surface relief havingelevated and/or depressed areas relative to the surface of the document,and to a method for producing such documents.

Such documents are, for example, papers of value, bank notes,certificates and identity cards. The latter are used as credit cards,bank cards, cash cards, entitlement cards or the like in a great varietyof areas, including e.g. cashless payments, access control systems and agreat variety of service systems. These identity cards generally havedata relating to the card owner which are applied during the so-calledpersonalization process. A widespread way of applying these data is theembossing method, by which the individual characters are embossed bymechanical dies that deform the card material (U.S. Pat. No. 3,363,346).One distinguishes between "high embossed data," which are embossed fromthe back of the card and exist in the form of raised areas on the frontof the card, and "deep embossed data," which are embossed from the frontof the card to the back. Deep embossed characters therefore exist in theform of depressed areas in the front of the card. To improve thevisibility of the individual characters, one additionally inks the apexareas (high embossing) or depressed areas (deep embossing) with a color,usually black, that contrasts clearly with the surroundings.

The particular advantage of these embossed card data is that the dataexisting in relief can at the same time be used as a printing block.When the card is used later, the data can thus be easily transferred tothe current voucher. The transfer is effected in "imprinter devices"into which the card and the voucher are inserted for the user data to bereproduced on the voucher via a mechanical embossing process usingcarbon paper or flimsy (U.S. Pat. No. 3,577,917). An internationalstandard fixes not only the position of the embossed data on theidentity card but also the form and the relief height thereof (ISOStandard 7811/1).

It has become apparent worldwide for some time that this way ofrepresenting the user-related data of an identity card, that isfinancially advantageous in terms of both production and subsequentpractical use, has the serious disadvantage that these data arerelatively poorly protected against attempted forgery. Since the cardmaterials are generally thermoplastics, in particular PVC, the embosseddata can be ironed flat relatively easily and the cards reembossed withdifferent data. The original inking can generally be removed usingcommercially available solvents and a forged card reinked with adifferent data set using commercial inks. Original cards, i.e. cardsthat are "authentic" in terms of their structure and getup, can thus beprovided with false user data with fraudulent intent quite easilywithout this being recognizable or testable by outsiders.

In order to counteract this easy forgeability and limit the resultingfinancial losses, there have been many proposals for solving thisproblem.

Some of these proposals aim at replacing mechanical high embossing byother methods for producing irreversible relief structures.

For example, Canadian Patent No. 995,274 discloses a method by which theembossed data only appear on one surface of the card. In this method,the personalization data are engraved into metal plates and transferredto the surface of the identity card during lamination of the card.During the laminating process the card material softens and flows intothe depressions in the metal plate without leaving any negative reliefon the back. This gives rise to characters that can also be used as aprinting block but can no longer be embossed back and changed in theconventional way.

However, this type of embossing is much more elaborate since a metalplate with the particular engraved personalization data must be producedfor each card and this personalization process is a method step thatcannot be separated from the card production.

Only U.S. Pat. No. 4,507,346 presents an identity card whose characterset to be used as a printing block can not only be provided in a simpleway, but is also present in an especially unforgeable form. The knownmethod proposes providing the identity card with a foamable plasticslayer containing appropriate foaming agents and then foaming this layerlocally to form the desired characters in a relief structure. Onepreferably uses a laser beam which generates in the foamable plasticsmaterial the heat necessary for triggering the foaming process oractivating the foaming agents. By appropriately selecting the plasticsmaterial, foaming agent and laser parameters, such as intensity, etc.,one can conduct this foaming process selectively to produce charactersthat conform to the standard in terms of their dimensions and reliefheight. At the same time, this foaming can involve a discoloration ofthe plastics material, so that one can dispense with the inkingoperation. Since the discoloration exists within the plastics materialitself and is furthermore irreversible, it is unforgeable and alsoresistant to abrasion.

Although a high degree of protection against forgery is reached by theknown card, its production involves providing foamable film layers whichcannot readily be used unchanged for commonly time-tested layerstructures.

According to another method (German laid-open print no. 34 09 761), oneapplies to the outer surface of an identity card an additional layerwhose thickness corresponds to the required relief height of the data.One then forms the characters by locally removing the material of thisadditional layer using a laser beam.

This method also requires the use of special layers which must show bothgood removability and good adhesive properties.

Other known methods aim at protecting the embossed data produced byconventional methods against falsification by taking additionalmeasures.

For example, U.S. Pat. No. 4,597,592 discloses a method for applying asecond data set identical to the embossed data set to the card materialin an irreversible form by means of a laser beam. By directly comparingthe embossed data set with the second invariable data set, one candetect the correctness of the embossed data without any auxiliary means.According to another embodiment (U.S. Pat. No. 4,597,593) one placesover the embossed data--also by means of a laser--a security pattern,e.g. a line pattern, which has typical inhomogeneities corresponding tothe embossed characters due to the surface structure and the resultingchange in the recording conditions. In particular after a backembossing,the original data are clearly recognizable due to this inhomogeneity inthe line pattern.

Both methods attain a high degree of protection against forgery, butthey require the use of a laser. Furthermore, these protective measuresare more suitable for visual testing and less suitable for machinetesting.

It is also known (German laid-open print no. 34 40 653) to additionallyapply thermosensitive substances to identity cards to be provided withembossed characters. Since a forger usually heats and thereby softensthe card material to make it easier to reverse the embossed structure,thermosensitive substances which change their color at temperatureswithin the range of the softening temperatures make such attemptedforgery visible.

An essential disadvantage of this method is that these temperatures atwhich the thermosensitive substances change their color must not bereached during production of the identity cards either. This makes itimpossible to use the conventional methods of producing identity cardswhich involving pressing the individual card layers together under theeffects of heat and pressure. Furthermore, this known card is notprotected against cold working, i.e. a reversal without simultaneousheating. Finally, the card also fails to meet the usual requirements interms of temperature resistance and will already show discoloration, forexample, in strong sunlight or if stored carelessly, e.g. in thevicinity of sources of heat. This may unfairly cast a suspicion ofmanipulation on the owner of the card.

Finally, German laid-open print no. 33 14 244 discloses various methodsof protecting embossed data from forgery which consist in particular inremoving layer material chemically or mechanically in the apex areas ofthe embossed characters, thereby exposing a deeper layer contrastingwith the surroundings. Another measure consists in introducing into theidentity card a layer provided with microcapsules that containchromogenic substances. During mechanical embossing these substances aresimultaneously released and produce a corresponding invariablediscoloration in the interior of the card.

The present invention is based on the problem of providing a documentbearing a surface relief, in particular in the form of embossedcharacters, that is easy and inexpensive to produce and allows for easyand reliable testing of both the document and the data applied theretoas to their authenticity and originality to protect the data againstfalsification. Another goal is to provide methods for producing suchdocuments.

This problem is solved by the features stated in the characterizing partof the independent claims. Advantageous developments are the subject ofthe subclaims.

A feature of the present invention is that relief structures of adocument, such as the embossed characters of an identity card to be usedas a printing block, are provided with at least one luminescentsubstance in such a way that the authenticity of the document and thecorrectness of the data can be ascertained by testing the presence, thespatial distribution and the properties of the luminescent substance(s)in terms of excitation and emission. One therefore preferably usesluminescent substances not accessible to the general public. Thesubstances can optionally also be used in a mixture of variousluminescent and nonluminescent substances that can only be analyzedusing considerable technical resources. The areas to be marked arepreferably the apex areas, in the case of high embossed characters, andthe bottoms of the depressions representing the characters, in the caseof deep embossed characters.

Although the use of luminescent substances for protecting papers ofvalue is known from a number of publications and, on the other hand, theproblem of protecting embossed data from forgery has existed for a longtime, the prior art stated above shows that solutions for protectingembossed characters were always sought elsewhere.

Only the invention provides a solution of surprising simplicity forprotecting embossed characters from forgery, without any need forchanging the process technology of the conventional production ofembossed characters in any way, as shall be explained in more detailbelow.

This solution also makes it possible to check not only whether theembossed data are falsified (no or incomplete luminescence) but also, atthe same time, whether they are authentic. The latter is done by testingthe specific and characteristic properties of the particular luminescentsubstances used. The tests directed to the various aspects can beperformed visually or by machine, depending on which luminescentsubstances are used for protection.

Furthermore, it is also possible to provide reliable protection againstforgery for embossed structures on papers of value, such as the blindembossed characters, patterns, signets, etc. always present on shares.

The characters provided with luminescent substances are also mostsuitable for machine reading, since the use of corresponding filters canminimize disturbances from surrounding light so that one obtains highcontrast in the read signal, i.e. a good signal-to-noise ratio. Theinvention thus offers a simple solution for machine reading ofuser-related data and their further processing, transmission, etc., inthe desired form. The elaborate and trouble-prone, usually mechanicalscanning of high embossed characters as known up to now (U.S. Pat. Nos.3,832,008, and 3,917,925) can thus be avoided in a simple manner.

Furthermore, a signal differing from card to card can be obtained from adata line of a high embossed data set provided with luminescentsubstance, for example, by an integral scanning of the entire data lineor parts thereof. Such signals can then be used in the known manner(U.S. Pat. No. 4,527,051) to detect the individual authenticity ofdocuments.

Not only embossed characters but also virtually any relief structures,even randomly arising relief structures, can be machine read in a simplemanner if the highly raised areas are provided with luminescentsubstance. By the indirect means of measuring the local distribution ofthe emission of the luminescent substance, one can thus ascertainstriking places in a surface relief using relatively simple means. Arelief structure introduced more or less randomly into the surface of adocument such as an identity card, or a randomly arising relief such assurface granulation, can be used to obtain such individual signals bydetecting the luminescent image by machine, processing it and depositingit as an authenticity characteristic e.g. in a magnetic stripe or anelectronic memory of an identity card. In a subsequent verificationoperation the luminescent or relief image is scanned and the dataobtained therefrom checked for similarity with the stored data.

In a preferred embodiment, the luminescent substance is transferred tothe raised areas of a document by the so-called hot embossing method,i.e. via a transfer band. In this hot embossing method, a transfer bandis coated with the substances to be applied to the document, whereby theband optionally bears both a visually contrasting color and theluminescent substance. It is thus possible, in one operation, to applyseveral substances simultaneously and fix them there, e.g. with the aidof an additional adhesive layer. The luminescent substance(s) and thelayer of contrasting color can be present in one layer in the form of amixture, or else in two or more superjacent and adjacent layers. Onepreferably selects an arrangement in which the transferred luminescentsubstances form the outer layer of the card, to prevent the excitationradiation and emission from being disturbed by the layer of color.

This transfer method is also particularly suitable for applying one ormore luminescent substances, preferably in the form of a multicolorluminescent pattern, to relief structures on the surface of a papercarrier, such as a share, bank note, etc., which are produced e.g. bysteel intaglio printing.

It is also particularly advantageous, for example, to use sublimablecolors and luminescent substances, since after evaporation by diffusionor migratin they penetrate into the plastics material and are thus fixedand not removable from the document without destroying it.

Further advantages, in particular advantageous developments, are theobject of the description of the inventive subject with reference to thefigures, in which

FIG. 1 shows an identity card from the front,

FIG. 2 shows a sectional view of this card,

FIGS. 3, 3a and 3b and 4 and 4a show various embodiments of a transferband,

FIG. 5 shows the sectional view of an identity card with deep embossedcharacters,

FIG. 6 shows a portion of an identity card with a schematic view of thesensor head of the scanning means,

FIG. 7 shows a signal obtained during scanning,

FIGS. 8 and 9 show further embodiments of the invention.

FIGS. 1 and 2 show, as an example of a document, an identity card 1 withthe typical information content. This includes e.g. statement 2 of theissuing credit institute, which is applied e.g. by printing technologyto card inlay 4. The card inlay is preferably covered on one or bothsides by a transparent cover film 5. Finally, the card bearsuser-related data 3 which are applied to the card in a relief form thatcan be used as a printing block. In the case of high embossing, thecharacters are embossed from back 6 of the card to front 7, so that theyappear in the form of elevations on the front of the card. In the caseof deep embossing, the characters are embossed from the front of thecard toward the back, so that they appear in the form of depressions onthe front of the card (FIG. 5). The embossed characters are made morevisible by being inked with contrasting, usually black, gold or silvercolor 8 (or 19 in FIG. 5).

These relief structures are now provided additionally with luminescentsubstance in the apex areas or the bottoms. This luminescent substancecan be directly mixed into color 8 for inking the embossed characters orapplied as separate layer 9. If the apex areas of the surface relief isto be inked, it is advisable to use the known hot embossing method, bywhich the layers to be provided on the card are first applied to acarrier band and then transferred from this band to the card usingpressure and heat. Due to the relief structure of the card, the layersof the carrier band are only transferred to those areas which come inclose contact with the band, i.e. in this case only the raised areas ofthe surface relief.

FIG. 3 shows such a transfer band 11, the layers being represented forthe sake of clarity at some distance apart and not true to scale.Carrier band 12 is preferably a mechanically very stable andthermostable plastics band, the preferred material being polyester. Alayer of varnish 13 is applied to this carrier band, later forming anouter cover layer of the card and protecting the layers therebelow, suchas adjacent layer of color 14, from abrasion and mechanical stress.Above-mentioned layer of color 14 contains the colors necessary toimprove visibility. The latter are usually black, gold- orsilver-colored pigments and the luminescent substance. The luminescentsubstances may be organic or inorganic, but they should expediently notbe available commercially. The luminescent substance can be selected,for example, so as to be visible not only to a machine but also to thehuman eye, e.g. having an emission in the IR and visible spectralranges. The mixing ratio of color pigments and luminescent substancesand their color constellation should be selected such that theexcitation light and/or emission light of the luminescent substance arepresent in sufficient intensity or will not be excessively absorbed bythe color pigments.

These layers of color and varnish can be fixed on the surface of theidentity card e.g. with the aid of an adhesive layer 15 which isactivated using heat and pressure. Another possibility is to usesublimable and/or migrating colors and luminescent substances whichevaporate during hot embossing, for example, and penetrate into adjacentlayers, in particular into the plastics material of a card.

A further embodiment of a transfer band is shown in FIG. 4. According tothis variation, the luminescent substance and the color pigments formseparate layers 16, 17, whereby layer 16 containing the luminescentsubstance is introduced between layer of varnish 13, which is later onthe outside, and layer of color 17. Since the luminescent substance isnot covered by color pigments here and is thus restricted in itsemissive power, the amount of substance required can be considerablyreduced and nevertheless a very visible or machine-detectable emissionobtained. The transfer band technique also offers a simple possibilityof applying luminescent substances that emit in different colors in anydesired, e.g. an iridescent, pattern, if the transfer band is providedwith a correspondingly designed luminescent layer. For example, thepattern can be selected here in such a way that two partial areas of thesurface relief appear luminescent in different colors and the two colorsexist side by side in an area therebetween, so that a pure luminescentcolor runs into the other pure luminescent color continuously or via asecondary color. Furthermore, fine lines or large-area signets, forexample, can be applied in one luminescent color over a differentcolored luminescent background, which are effective in suitable surfacestructures, e.g. fine screens.

In FIG. 3a, two luminescent substances are contained in a single layer16. Alternatively, two luminescent substances may be incorporated intoseparate layers 16a and 16b as shown in FIGS. 3b and 4a. The color orink may be in a layer 17 which is separate from the luminescent materialas shown in FIGS. 4 and 4a.

The layer of varnish covering the luminescent substance may be e.g. asynthetic resin varnish hardenable under UV light, which is hardenedafter being transferred to the card and thus gives the card surfacesufficient hardness. This protects the luminescent substance againstmechanical stress, in particular abrasion, during the subsequent dailyuse of the card.

Application of the luminescent substance by the hot embossing method hasin particular the advantange that it makes it possible to apply both thecontrasting color and the luminescent substance in one operation, sothat no additional procedural steps are required during card production.A further advantage of the hot embossing method is that this method canalso be used for inking very fine structures, so that almost any reliefstructures can be provided with luminescent substance in the desiredform.

Instead of this hot embossing method, other inking techniques known e.g.from the letterpress method can also be used. For example, theluminescent substances can be applied via a roller or similar means.

FIG. 5 shows a partial sectional view of an identity card provided withdeep embossed characters 18. In the case of these characters, theluminescent substance and also the contrasting color are introduced intobottoms 19 of the relief structure. Here, too, the luminescent substanceand the color can be applied in the same operation. For this purpose, anappropriately equipped ink ribbon is preferably introduced between theembossing die and the identity card during the embossing of thecharacters, and the color transferred and fixed usually by mechanicalmeans. Since the luminescent substance exists here in a protectedposition, i.e. in these valley bottoms, one can generally dispense withan additional varnish cover, in particular a UV varnish cover. However,the luminescent substance can also be applied to back 20 of the cardpreferably by the above-mentioned hot embossing method, whereby aluminescent substance is appropriate here if it is transparent undernonactinic light. Since the characters appear in mirror writing when theluminescent substance is excited, this method is mainly suitable formachine testing.

The embossed characters can be tested and machine read in a simple waywith sensors that respond to the luminescent light. By selectingsuitable filters that make the sensors respond solely to the emissionlight, one obtains a reliable detection since the entire ambient lightof other wavelength ranges is eliminated. This allows not only for thecharacters to be read in a simple manner but also for easy authenticitytesting, since the reading device only responds when luminescentsubstances with the necessary emission properties are actually present.

The luminescence distribution on the card can be used not only fordetecting characters as such and determining the user data, but also fordetecting characters as such and determining the user data, but also forobtaining an individual signal differing from card to card. As shown inFIG. 6, a sensor is used here, for example, whose scan area has theshape of rectangle 21. When this sensor is directed over data line 22and the light received in the scan area recorded in the form of anintensity distribution, this results in a curve as shown basically byway of example in FIG. 7. The trace of the curve is determined by theshape of the characters, for instance, but also by manufacturing andprocess tolerances during application of the luminescent substance andby the scanning geometry of the sensor head. This analog signal can nowbe recorded directly on the card or else digitized, compressed and,preferably also in an encoded form, recorded into a storage medium ofthe card (magnetic track, electronic memory, etc.). During thesubsequent use of the card, the data line is then scanned again in thesame form and the scanned result compared with the one recorded before.Such methods of determining the authenticity of data carriers are knownfrom German patent no. 28 58 266 or 28 29 778.

The inventive solution, i.e. to equip relief structures partly withluminescent substances, is not limited to high (deep) embossed data, butcan also be used to protect any relieflike surface areas.

Such relief structures can e.g. also be randomly arising structures.Laminating plates which have been given a rough surface e.g. by sandblasting, transfer their surface roughness to the card surface. One canmake this barely reproducible surface structure "visible" to a machineor to the human eye in the form of a luminescence image by applyingluminescent substance to the raised areas, the spatial distribution ofthe relief peaks being a feature that clearly characterizes theparticular structure. This relief structure is thus recognizable, andcan be tested for changes, in an unambiguous and reproducible form.

If this structure is scanned when the card is issued and the resultstored on the card or in an authorization office, after possibleprocessing of the data (digitization, reduction, encoding, linking withother card data and other information, etc.), this card can be checkedin a simple way at a later time as to the specific surface structure andits intactness. Attempts to change inside card data by removing thecover layer of the card with mechanical, thermal or chemical means canthus be clearly recognized, since such attempts cannot be performedwithout destroying or changing the card surface and thus its reliefstructure.

FIG. 8 shows a portion of a card surface 30 in which protruding peakareas 31 of the surface structure are provided with luminescentsubstance 32. Although the luminescent substance is clearly shown, itcan of course be invisible (transparent) at least under nonactiniclight, so that the card has its commonly known appearance in its usualsurroundings and the luminescence and thus the relief structure are onlydetectable by machine and/or visually after excitation under IR light,UV light or other excitation sources.

The relief structure with an irregular, random character can--as alreadymentioned--be obtained by appropriately pretreated laminating plates orplate inserts, whereby the number of plates used for productionconstitutes a definite repeating rate. Cutting tolerances and selectiveinterventions during triggering, etc., can reduce the probability of twoor more "identical" cards coming about to a reasonable minimum.

The laminating plates and/or inserts which are introduced between thecard and the actual laminating plate can be provided with any desiredrelief structures by mechanical methods (e.g. sand blasting), chemicalmethods (e.g. etching) and other known methods.

The relief structures can also be produced directly on the document,paper of value, card, etc., by the same or different means. In the sameway structures can thus be provided in the outer surface e.g. using arandom-controlled laser beam by melting, decomposition, evaporation ofplastics or other materials. Similarly, one can locally foam foamableplastics materials, use appropriating printing techniques (steelintaglio printing, blinding techniques, etc.), vapor-metallize material,etc., to create structured surfaces which are then provided with aluminescent substance according to the invention. In particular due tothe random structure, the document then has an authenticity feature thatis inimitable, or cannot be imitated by reasonable efforts.

Since the random structure itself already provides sufficient protectionagainst forgery, one can use commercially available luminescentsubstances.

When evaluating the surface structure of an identity card, it is notnecessary, as shown in FIG. 9, to scan the entire structured surface 33of the card. It usually suffices to scan the card e.g. only along atrack 34 or within an area 35, since a signal obtained therefrom alreadyhas sufficient "individuality." If one records on the data carrier inwhat area the relief structure is evaluated, one obtains furtherindividualization that is not recognizable to an outsider and isselected anew from card to card or from test to test. In this way onecan select very striking areas or take account of acceptable changes inthe relief structure that exist from test to test (ageing).

The luminescent substance is preferably also applied only along thistrack 34. In the hot embossing method, one can determine the track widthin a simple way by selecting the transfer band width accordingly, andalso the placement of the track by the positioning of the band relativeto the card.

Methods and suitable sensors for detecting luminescence by measurementtechniques are known as such, in particular from the above-mentionedGerman patent nos. 28 29 778 and 28 58 266.

We claim:
 1. In a document with a surface relief having raised zones inrelation to the main surface of the document;said zone being localdeformations of the document itself; wherein the improvement comprisesat least one luminescent coating material being at least partiallypresent only on the raised zones of the relief.
 2. In a document with asurface relief having raised and depressed zones in relation to the mainsurface of the document;said zones being local deformations of thedocument itself; wherein the improvement comprises at least oneluminescent coating material being at least partially present only onthe raised and depressed zones of the relief.
 3. In a document with asurface relief having depressed zones in relation to the main surface ofthe document;said zones being local deformations of the document itself;wherein the improvement comprises at least one luminescent coatingmaterial being at least partially present only on the depressed zones ofthe relief.
 4. The document of claims 1, 3, or 2, characterized in thatthe luminescent substance is covered by a layer of varnish.
 5. Thedocument of claim 4, characterized in that the layer of varnish consistsof a polymerizable resin.
 6. The document of claim 4, characterized inthat the luminescent substance is present at least partially in thedocument material.
 7. The document of claims 1, 3 or 2, characterized inthat the luminescent substance present in the surface relief of thedocument is transparent in nonactinic light.
 8. The document of claims1, 3 or 2, characterized in that the luminescent substance is onlypresent in a partial area of the surface relief in the form of a narrowband.
 9. The document, according to claim 1, wherein the reliefcomprises embossed characters which form elevations on and relative tothe surface of the document whereby the luminescent substance is presenton the apex areas of these elevations.
 10. The document of claim 9,wherein two or more luminescent substances emitting in differentspectral ranges are present in the surface relief of the document toform multicolor luminescent patterns.
 11. The document according toclaim 10, wherein the surface of the embossed characters is additionallyinked with visible color contrasting with the surroundings.
 12. Thedocument according to claim 9, wherein the surface of the embossedcharacters is additionally inked with a visible color contrasting withthe surroundings.
 13. The document according to claims 1, 3 or 2,wherein the relief forms a random pattern.
 14. The document according toclaim 13, wherein the surface of the relief is additionally inked withvisible color contrasting with the surroundings.
 15. The document ofclaim 13, wherein two or more luminescent substances emitting indifferent spectral ranges are present in the surface relief of thedocument to form multicolor luminescent patterns.
 16. The document ofclaims 1, 3, or 2, wherein two or more luminescent substances emittingin different spectral ranges are present in the surface relief of thedocument to form multicolor luminescent patterns.
 17. The documentaccording to claim 16, wherein the surface of the relief is additionallyinked with visible color contrasting with the surroundings.
 18. Thedocument according to claim 16, wherein the luminescent substances arepresent in separate layers.
 19. The document according to claims 1, 3,or 2, wherein the surface of the relief is additionally inked a visiblecolor contrasting with the surroundings.
 20. The document according toclaim 19, wherein the luminescent substances and ink pigments arepresent in separate layers.
 21. The document according to claim 3,wherein the relief comprises embossed characters which form depressionson and relative to the surface of the document whereby the luminescentsubstance is present on the lowermost parts of the depressions.
 22. Thedocument according to claim 21, wherein the surface of the embossedcharacters is additionally inked with visible color contrasting with thesurroundings.
 23. The document of claim 21, wherein two or moreluminescent substances emitting in different spectral ranges are presentin the surface relief of the document to form multicolor luminescentpatterns.